Abstract: An annular time-to-digital converter includes a pulse shaper that shapes an input start pulse and an input stop pulse to form fixed-width pulses for output. The annular time-to-digital converter also includes at least two differential comparing units that enable, during matching enabling, triggers of the differential comparing units to set setting ends to 1. A circle counter counts the number of times a pulse is propagated in a loop. A matching enabling logical device generates a matching enabling signal, and sends the generated matching enabling signal to comparing enabling ports of the differential comparing units. At least two in-loop position encoders find a position of a first matched unit according to matching signals sent by the differential comparing units. Result recording registers record the number of circles and in-loop positions when matching occurs. High resolution is realized using a differential chain, and wafer area is saved by the annular design.

Abstract: A water meter casing and manufacturing process thereof are provided. The water meter casing comprises a middle casing (1), a water inlet port (2) and a water outlet port (3), which are separate parts, wherein a water inlet (4) and a water outlet (5) where the water inlet and outlet ports (2, 3) are arranged are respectively provided at the two sides of the middle casing (1), and a support ring (6) is also provided in the inner cavity of the middle casing (1). The manufacturing process of the water meter casing relates to a method of forming the water meter casing by high pressure hydraulic bulging. The manufacturing process is simple and easy to carry out, and it presents the advantage of low cost.

Abstract: A water meter casing and manufacturing process thereof are provided. The water meter casing comprises a middle casing (1), a water inlet port (2) and a water outlet port (3), which are separate parts, wherein a water inlet (4) and a water outlet (5) where the water inlet and outlet ports (2, 3) are arranged are respectively provided at the two sides of the middle casing (1), and a support ring (6) is also provided in the inner cavity of the middle casing (1). The manufacturing process of the water meter casing relates to a method of forming the water meter casing by high pressure hydraulic bulging. The manufacturing process is simple and easy to carry out, and it presents the advantage of low cost.